Facebook Tests A Redesign -- Screenshots

“We are currently testing different designs of the News Feed and the home page with select users. The tests help us understand if we can make it easier for users to balance both the most important and the most recent information from people they’re connected to.”

The biggest change is the addition of a "View Top News" option in the News Feed. We assume that this is supposed to help increase the noise to signal ratio in the News Feed, which some users complain has been cluttered since Facebook began including every little update in real time.